The objective of the Colon Cancer Risk and Prevention Clinic is to bring together pedigrees with a high incidence of colon polyps and colon cancer for the purpose of identifying new genes predisposing to these illnesses. Excess familial clustering is common in colon cancer, but only a small fraction of cases arise from the very few known genetic syndromes. Kindred studies have suggested that common familial clustering arises from inherited susceptibility, but the genes responsible for this inheritance remains to be identified. Dr. Burt and his colleagues are utilizing unique Utah family resources to identify large kindreds with high familial risk for colon cancer, determine which of these kindreds have one of the known genetic syndromes, examine members of non-defined families with colonoscopy, and then perform genetic linkage studies using both cancer and polyps as "markers" for the presence of an abnormal gene.